Tuning Into More Compact Laser Designs

Tuning Into More Compact Laser Designs
March 13, 2017 | Source: Agency for Science, Techniolgy and Research (A*STAR); Yan. Z, Sun, B., et al.

A laser developed at A*STAR can produce infrared beams over an unprecedented range of wavelengths.

A*STAR scientists have developed a unique fast-pulsing fiber laser that has the widest wavelength output to date1. This type of laser could replace several fixed-wavelength lasers and form the basis of compact devices useful for a range of medical and military applications.

The team developed an all-fiber laser, constructed similarly to a fiber-optic cable. The key component is a glass tube, whose core is doped with atoms that act as a gain medium — a material from which energy is transferred to boost the output power of the laser — through which light particles, or ‘photons’, travel. The doping atoms are selected according to the specific wavelengths of light that they will absorb, store and then release, creating an efficient, controllable output beam.

“To date, most tunable all-fiber pulsed lasers achieve a maximum tuning range of about 50 nanometers,” says Xia Yu from the A*STAR Singapore Institute of Manufacturing Technology, who worked on the project with her team and her collaborator Qijie Wang from Nanyang Technological University. “We have achieved a widely-tunable laser in the mid-infrared wavelength band, with a range of 136 nanometers (from 1,842 to 1,978 nanometers). We used thulium as the doping atom; this generates a laser that operates in the eye-safe range, meaning it could have medical and military applications.”